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Mastoiditis

WORLD SKULL BASEE-LEARNING MATERIAL

Mastoiditis 1

Mastoiditis

MastoiditisClassification and external resources

Side view of head, showing surface relations of bones. (Mastoid process labeled near center.)

ICD-10 H70 [1]

ICD-9 383.0 [2]-383.1 [3]

DiseasesDB 22479 [4]

MedlinePlus 001034 [5]

eMedicine emerg/306 [6] ped/1379 [7]

MeSH D008417 [8]

Mastoiditis is the result of an infection that extends to the air cells of the skull behind the ear. Specifically, it is aninflammation of the mucosal lining of the mastoid antrum and mastoid air cell system inside[9] the mastoid process,that portion of the temporal bone of the skull that is behind the ear and which contains open, air-containing spaces.[][]

It is usually caused by untreated acute otitis media (middle ear infection) and used to be a leading cause of childmortality. With the development of antibiotics, however, mastoiditis has become quite rare in developed countrieswhere surgical treatment is now much less frequent and more conservative, unlike former times.[] Untreated, theinfection can spread to surrounding structures, including the brain, causing serious complications.[]

Mastoiditis 2

FeaturesSome common symptoms and signs of mastoiditis include pain, tenderness, and swelling in the mastoid region.There may be ear pain (otalgia), and the ear or mastoid region may be red (erythematous). Fever or headaches mayalso be present. Infants usually show nonspecific symptoms, including anorexia, diarrhea, or irritability. Drainagefrom the ear occurs in more serious cases, often manifest as brown discharge on the pillowcase upon waking.[][]

Diagnosis

Mastoiditis with subperiostal abscess

The diagnosis of mastoiditis is clinical—based on the medical historyand physical examination. Imaging studies provide additionalinformation; The standard method of diagnosis is via MRI scanalthough a CT scan is a common alternative as it gives a clearer andmore useful image to see how close the damage may have gotten to thebrain and facial nerves. Planar (2-D) X-rays are not as useful. If thereis drainage, it is often sent for culture, although this will often benegative if the patient has begun taking antibiotics. Exploratorysurgery is often used as a last resort method of diagnosis to see themastoid and surrounding areas.[][]

Pathophysiology

The pathophysiology of mastoiditis is straightforward: bacteria spreadfrom the middle ear to the mastoid air cells, where the inflammationcauses damage to the bony structures. Streptococcus pneumoniae,Streptococcus pyogenes, Staphylococcus aureus, Haemophilus influenzae, and Moraxella catarrhalis are the mostcommon organisms recovered in acute mastoiditis. Organisms that are rarely found are Pseudomonas aeruginosaand other Gram-negative aerobic bacilli, and anaerobic bacteria.[10] P. aeruginosa, Enterobacteriaceae, S. aureus andanaerobic bacteria (Prevotella, Bacteroides, Fusobacterium, and Peptostreptococcus spp. ) are the most commonisolates in chronic mastoiditis.[] Rarely, Mycobacterium species can also cause the infection. Some mastoiditis iscaused by cholesteatoma, which is a sac of keratinizing squamous epithelium in the middle ear that usually resultsfrom repeated middle-ear infections. If left untreated, the cholesteatoma can erode into the mastoid process,producing mastoiditis, as well as other complications.[]

Mastoiditis 3

Mastoid cells of Lenoir

Prevention and treatment

In general, mastoiditis is rather simple toprevent. If the patient with an ear infectionseeks treatment promptly and receivescomplete treatment, the antibiotics willusually cure the infection and prevent itsspread. For this reason, mastoiditis is rare indeveloped countries. However, the rise of"superbugs" that are resistant toconventional antibiotics increases the riskthat ear infections will worsen intomastoiditis. Most ear infections occur ininfants as the eustachian tubes are not fullydeveloped and don't drain readily.In the United States the primary treatmentfor mastoiditis is administration of intravenous antibiotics. Initially, broad-spectrum antibiotics are given, such asceftriaxone. As culture results become available, treatment can be switched to more specific antibiotics directed atthe eradication of the recovered aerobic and anaerobic bacteria.[] Long-term antibiotics may be necessary tocompletely eradicate the infection.[] If the condition does not quickly improve with antibiotics, surgical proceduresmay be performed (while continuing the medication). The most common procedure is a myringotomy, a smallincision in the tympanic membrane (eardrum), or the insertion of a tympanostomy tube into the eardrum.[] Theseserve to drain the pus from the middle ear, helping to treat the infection. The tube is extruded spontaneously after afew weeks to months, and the incision heals naturally. If there are complications, or the mastoiditis does not respondto the above treatments, it may be necessary to perform a mastoidectomy: a procedure in which a portion of the boneis removed and the infection drained.[]

Attack triangle in mastoidectomies

Prognosis

With prompt treatment, it is possible to curemastoiditis. Seeking medical care early isimportant. However, it is difficult forantibiotics to penetrate to the interior of themastoid process and so it may not be easy tocure the infection; it also may recur.Mastoiditis has many possiblecomplications, all connected to the infectionspreading to surrounding structures. Hearingloss is likely, or inflammation of thelabyrinth of the inner ear (labyrinthitis) mayoccur, producing vertigo and an ear ringingmay develop along with the hearing loss,making it more difficult to communicate.The infection may also spread to the facial nerve (cranial nerve VII), causing facial-nerve palsy, producing weakness

or paralysis of some muscles of facial expression, on the same side of the face. Other complications include Bezold's abscess, an abscess (a collection of pus surrounded by inflamed tissue) behind the sternocleidomastoid muscle in the

Mastoiditis 4

neck, or a subperiosteal abscess, between the periosteum and mastoid bone ( resulting in the typical appearance of aprotruding ear). Serious complications result if the infection spreads to the brain. These include meningitis(inflammation of the protective membranes surrounding the brain), epidural abscess (abscess between the skull andouter membrane of the brain), dural venous thrombophlebitis (inflammation of the venous structures of the brain), orbrain abscess.[][]

EpidemiologyIn the United States and other developed countries, the incidence of mastoiditis is quite low, around 0.004%,although it is higher in developing countries. The most common ages affected are 2 months - 13 months, as it isduring that age that ear infections are most common. Males and females are equally affected.[]

References[1] http:/ / apps. who. int/ classifications/ icd10/ browse/ 2010/ en#/ H70[2] http:/ / www. icd9data. com/ getICD9Code. ashx?icd9=383. 0[3] http:/ / www. icd9data. com/ getICD9Code. ashx?icd9=383. 1[4] http:/ / www. diseasesdatabase. com/ ddb22479. htm[5] http:/ / www. nlm. nih. gov/ medlineplus/ ency/ article/ 001034. htm[6] http:/ / www. emedicine. com/ emerg/ topic306. htm[7] http:/ / www. emedicine. com/ ped/ topic1379. htm#[8] http:/ / www. nlm. nih. gov/ cgi/ mesh/ 2013/ MB_cgi?field=uid& term=D008417[9] Diseases of ear nose & throat by PL dhingra & shruti dhingra. published by elsevier

Further reading• Durand, Marlene & Joseph, Michael. (2001). Infections of the Upper Respiratory Tract. In Eugene Braunwald,

Anthony S. Fauci, Dennis L. Kasper, Stephen L. Hauser, Dan L. Longo, & J. Larry Jameson (Eds.), Harrison'sPrinciples of Internal Medicine (15th Edition), p. 191. New York: McGraw-Hill

• Cummings CW, Flint PW, Haughey BH, et al. Otolaryngology: Head & Neck Surgery. 4th ed. St Louis, Mo;Mosby; 2005:3019-3020.

• Mastoiditis E Medicine (http:/ / emedicine. medscape. com/ article/ 966099-overview)

External links• Radiology (http:/ / rad. usuhs. edu/ medpix/ cow_image. html?mode=cow_viewer& pt_id=14189&

imageid=58182) Mastoiditis, MRSA, Sinus thrombosis

Article Sources and Contributors 5

Article Sources and ContributorsMastoiditis  Source: http://en.wikipedia.org/w/index.php?oldid=553779498  Contributors: 2004-12-29T22:45Z, Alex.tan, Anatomist90, Anthonyhcole, Arcadian, Aude, Awien, Barek, CDN99,CSWarren, CambridgeBayWeather, Cortneyswensen, D'Agosta, Darrkwings, DeadlyAssassin, Dgshearer, Dribrook, Drjt87, Eleassar, Gil Dawson, Hannah burns, Isaac Sanolnacov, JeanneMish,John of Reading, Kingpin13, Knowledge Seeker, LarryJeff, Mdscottis, Mel Etitis, Mike2vil, Negamary, Nehwyn, Nietzsche 2, Nono64, Oloddin, Open2universe, Russthomas1515, SKLAU,SeoMac, Skt.diaz, TylerDurden8823, Verdatum, WJBscribe, WhatamIdoing, William Avery, Wouterstomp, Xnuala, Zarvok, 55 anonymous edits

Image Sources, Licenses and ContributorsFile:Gray1193.png  Source: http://en.wikipedia.org/w/index.php?title=File:Gray1193.png  License: Public Domain  Contributors: Arcadian, M.Komorniczak, MysidFile:Mastoiditis1.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Mastoiditis1.jpg  License: Creative Commons Attribution-ShareAlike 3.0 Unported  Contributors: B. WelleschikFile:Mastoid cells of Lenoir.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Mastoid_cells_of_Lenoir.jpg  License: Creative Commons Attribution-Sharealike 3.0  Contributors:User:Anatomist90File:Attack triangle in mastoidectomies.jpg  Source: http://en.wikipedia.org/w/index.php?title=File:Attack_triangle_in_mastoidectomies.jpg  License: Creative CommonsAttribution-Sharealike 3.0  Contributors: User:Anatomist90

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